In a TNPCB survey, the number of particulate matter that lies suspended in air was found to be drastically lower around this Deepavali as compared to that of the same period last year.
Particulate matter comprises solid and liquid particles suspended in air many of which are hazardous. It includes both organic and inorganic particles, such as dust, pollen, soot, smoke, and liquid droplets.
An ambient air quality survey conducted by the Tamil Nadu Pollution Control Board (TNPCB) in five places across Chennai, before and during the festival, noted that there has been a tenfold decrease in PM10 (particulate matter 10 micrometers or less in diameter) levels this year as compared to last year. The levels of sulfur dioxide (SO2), nitrogen oxides(NOx) and PM2.5 (particulate matter 2.5micrometers or less in diameter) have not seen much of a difference.
The TNPCB had scrutinised the air quality and noise levels in Triplicane, Besant Nagar, Nungambakkam, Sowcarpet and T Nagar to monitor the impact of the celebrations on air quality and noise levels as per the guidelines given by the Central Pollution Control Board based on the Supreme Court order instructing to carry out the survey for 14 days across cities.
Even though the state government had restricted the bursting of crackers to one hour in the morning and one hour at night, many pockets across the city chose not to follow it. The restriction, however, reduced the number of crackers being burst and brought the pollution levels this year more or less under control, the board claimed.
As per the TNPCB findings, the PM10 results, this year, ranged from 48 to 114 microgram/m3 while it ranged from 387 to 777 microgram/m3 last year. Officials claimed that the values were well within the limit in all stations on the day of Deepavali, except in Sowcarpet and that the prescribed standard is 114 microgram/m3. The gaseous pollutants namely sulphur dioxide and nitrogen dioxide were also found to be well within the prescribed standard of 80 microgram/m3 on both days.
The noise levels too were lower this year than last year, the officials claimed, adding that it is mainly a result of the Supreme Court’s guidelines and continuous monitoring by the police.